*{
    margin: 0;
    padding: 0;
}
.container{
    width:800px;
    height:800px;
    background-color: aqua;
}
.redbox,.greenbox,.bluebox{
    width: 200px;
    height:200px;
}
.redbox{
    background-color: red;
    float: right;
}
.greenbox{
    background-color: green;
    float:left;
}
.bluebox{
    background-color: blue;
    float: left;
}